“With this initiative the museum finally has the three floors it should have had in the original plans, when it was opened in 1942,” said Giammarusti.

“This is a symbol of the rebirth of culture from destruction that is all the more important today as ISIS destroys the great artefacts of Syria and Iraq.”

The archaeological museum suffered damage from shellfire and flooding during the conflict which ran from 1975-1990.

Located on the Green Line which divided the mainly Muslim west from the Christian east of the city, the building was used as military barracks. The most vulnerable objects in the collection were hidden in basement storerooms and the lower level was sealed up. Larger objects and mosaics were encased in concrete for protection.

The two upper floors have been open to the public since 1999, following a major restoration campaign led by the Lebanese culture ministry, directorate general of antiquities and National Heritage Foundation.

The new underground displays range from prehistory to the Ottoman Empire and include 31 Phoenician human-shaped sarcophagi carved in marble, the world’s largest such collection.

Also on show is the 1,800-year-old Roman tomb of Tyre, after its frescoed surfaces were restored by Italian conservators in 2010-11. Three medieval mummified bodies are also on view after analysis and restoration at the Eurac research centre in Bolzano, Italy.